vibration

O.K.

So I take my boat out Saturday morning and everything is fine. After about an hour and a half of riding I start to feel a small vibration in the boat. I don't think anything of it. About an hour later of pulling friends the vibration gets worse. I decided that something was wrong and that I needed to pull the boat out of the water. I inspected the prop to see if I had hit something and it looks brand new with no dents or dings. I then inspect the shaft which has no appearent damage. Before I took the boat out of the water I put it in neutral and ran the motor..it had no vibration when in neutral, but when put in either reverse or forward, it did.

Later that morning I drove to the shop to ask around about what they thought it could be. The first thing that came to mind was a bent prop shaft. The manager asked if I had driven through any shallow water. I did not and let him know. He then tells me that I probably did and that if it is the shaft it will not be covered under the Tige warrenty. Granted the shop has not looked at the boat, it goes in Thurs., but, why would this not be covered if it is the problem. I do not remember going through shallow water and the prop is spotless. We also have a mud bottom lake, which I think would make it hard to bend a shaft if I did accedently go into low water. Any clues as to what else it might be?

By the way, I have an 04 DD Tige 21I.

Mike

Did you run the boat in gear with the engine cover open to see if you could identify where the problem is coming from ?

You might take a look at the motor mounts too. If they break it can bend your shaft.

or if your motor is not aligned properly it will vibrate.

Walt,

I did run the boat in gear with the cover open, but could not see anything out of the ordinary. I looked at the mounts and they are solid.

I was wondering if the shaft could just be misaligned, or if a bushing or bearing is out of whack? This problem is no fun. The boat only has 50 hours on it and although it is an 04' it has only been run this season.

Also, could a bent prop cause vibration in the boat, I did notice that the boat's top speed after the vibration started was only 38 mph. I was wondering if the prop could be bent, but look fine as far as dings and stuff goes.

Ed has a good point and a really easy way to find out if it's the prop is get a loaner and change it and see if it goes away.

Bent prop or shaft or strut could all be the problem. You could have hit something in the water and not known it happens all the time.
This would not be covered by any manufactures warranty.

It it is an alignment problem it should be covered.


It it is an alignment problem it should be covered.

My guess you hit something

I have seen props bent really bad without bending the strut or drive shaft. I would be surprised if you hit something and bent the shaft or strut without visible damage to the prop. You said the boat would only go 38mph after the vibration started. Was the engine running full rpm? Were you at full throtle or holding back due to vibration? If engine is at full rpm and boat speed is reduced then either the prop has reduced pitch due to bending or the transmission/drive train is slipping. Either of those could cause vibration.

Even mud bottom lakes can bend a prop, and the mud can cause a bend where it does not nick or show any visable damage.

Check prop first. Same thing happened to me and it ended up being the prop. Everything seemed cool by looking at it had no nicks or dings but we changed it out and whaalaaa, no more vibration.

not all dings in props are visable to the naked eye! the smallest ding on the edge can cause it.

Just a ideal, put some lube in the strut bearings and then hook your water up to the water pump and test the drive train out of the water. A bent prop won't vibrate out of the water. A bent shaft, when you turn the prop by hand will spin free and then hit a hard spot. It should be smooth the full 360 dergrees. Look at your prop from the front view, the way the water flows sometimes you can see a variation that way. It doesn't take much at all to mess a prop up, its good to have a spare prop around, then you could switch them and find out for sure. Good Luck

I had a similar problem, in a mud bottom lake you can drive through the silt or soft mud and it will take some of the cup out of the prop. this will cause a vibration and higher RPM and less speed. There are many places that can fix your prop without you needing to buy a new one. Try James Propeller in Dallas http://www.jamespropeller.com/ You can send them your prop and have it back within the week in most cases. Also check and make sure your prop is not sitting back to far on the shaft rubbing the strut. That seems to be a problem with Tige also, and if you find a way to correct it let me know.

Thanks guys,

I will check the prop in the morning.